gem5  v22.1.0.0
mem_delay.cc
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37 
38 #include "mem/mem_delay.hh"
39 
40 #include "params/MemDelay.hh"
41 #include "params/SimpleMemDelay.hh"
42 
43 namespace gem5
44 {
45 
46 MemDelay::MemDelay(const MemDelayParams &p)
47  : ClockedObject(p),
48  requestPort(name() + "-mem_side_port", *this),
49  responsePort(name() + "-cpu_side_port", *this),
50  reqQueue(*this, requestPort),
51  respQueue(*this, responsePort),
52  snoopRespQueue(*this, requestPort)
53 {
54 }
55 
56 void
58 {
60  fatal("Memory delay is not connected on both sides.\n");
61 }
62 
63 
64 Port &
65 MemDelay::getPort(const std::string &if_name, PortID idx)
66 {
67  if (if_name == "mem_side_port") {
68  return requestPort;
69  } else if (if_name == "cpu_side_port") {
70  return responsePort;
71  } else {
72  return ClockedObject::getPort(if_name, idx);
73  }
74 }
75 
76 bool
78 {
79  return responsePort.trySatisfyFunctional(pkt) ||
81 }
82 
83 MemDelay::RequestPort::RequestPort(const std::string &_name, MemDelay &_parent)
84  : QueuedRequestPort(_name, &_parent,
85  _parent.reqQueue, _parent.snoopRespQueue),
86  parent(_parent)
87 {
88 }
89 
90 bool
92 {
93  // technically the packet only reaches us after the header delay,
94  // and typically we also need to deserialise any payload
95  const Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
96  pkt->headerDelay = pkt->payloadDelay = 0;
97 
98  const Tick when = curTick() + parent.delayResp(pkt) + receive_delay;
99 
100  parent.responsePort.schedTimingResp(pkt, when);
101 
102  return true;
103 }
104 
105 void
107 {
108  if (parent.trySatisfyFunctional(pkt)) {
109  pkt->makeResponse();
110  } else {
111  parent.responsePort.sendFunctionalSnoop(pkt);
112  }
113 }
114 
115 Tick
117 {
118  const Tick delay = parent.delaySnoopResp(pkt);
119 
120  return delay + parent.responsePort.sendAtomicSnoop(pkt);
121 }
122 
123 void
125 {
126  parent.responsePort.sendTimingSnoopReq(pkt);
127 }
128 
129 
131 ResponsePort(const std::string &_name, MemDelay &_parent)
132  : QueuedResponsePort(_name, &_parent, _parent.respQueue),
133  parent(_parent)
134 {
135 }
136 
137 Tick
139 {
140  const Tick delay = parent.delayReq(pkt) + parent.delayResp(pkt);
141 
142  return delay + parent.requestPort.sendAtomic(pkt);
143 }
144 
145 bool
147 {
148  // technically the packet only reaches us after the header
149  // delay, and typically we also need to deserialise any
150  // payload
151  Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
152  pkt->headerDelay = pkt->payloadDelay = 0;
153 
154  const Tick when = curTick() + parent.delayReq(pkt) + receive_delay;
155 
156  parent.requestPort.schedTimingReq(pkt, when);
157 
158  return true;
159 }
160 
161 void
163 {
164  if (parent.trySatisfyFunctional(pkt)) {
165  pkt->makeResponse();
166  } else {
167  parent.requestPort.sendFunctional(pkt);
168  }
169 }
170 
171 bool
173 {
174  const Tick when = curTick() + parent.delaySnoopResp(pkt);
175 
176  parent.requestPort.schedTimingSnoopResp(pkt, when);
177 
178  return true;
179 }
180 
181 
182 
183 SimpleMemDelay::SimpleMemDelay(const SimpleMemDelayParams &p)
184  : MemDelay(p),
185  readReqDelay(p.read_req),
186  readRespDelay(p.read_resp),
187  writeReqDelay(p.write_req),
188  writeRespDelay(p.write_resp)
189 {
190 }
191 
192 Tick
194 {
195  if (pkt->isRead()) {
196  return readReqDelay;
197  } else if (pkt->isWrite()) {
198  return writeReqDelay;
199  } else {
200  return 0;
201  }
202 }
203 
204 Tick
206 {
207  if (pkt->isRead()) {
208  return readRespDelay;
209  } else if (pkt->isWrite()) {
210  return writeRespDelay;
211  } else {
212  return 0;
213  }
214 }
215 
216 } // namespace gem5
The ClockedObject class extends the SimObject with a clock and accessor functions to relate ticks to ...
Tick recvAtomicSnoop(PacketPtr pkt) override
Receive an atomic snoop request packet from our peer.
Definition: mem_delay.cc:116
bool recvTimingResp(PacketPtr pkt) override
Receive a timing response from the peer.
Definition: mem_delay.cc:91
void recvTimingSnoopReq(PacketPtr pkt) override
Receive a timing snoop request from the peer.
Definition: mem_delay.cc:124
void recvFunctionalSnoop(PacketPtr pkt) override
Receive a functional snoop request packet from the peer.
Definition: mem_delay.cc:106
RequestPort(const std::string &_name, MemDelay &_parent)
Definition: mem_delay.cc:83
bool recvTimingReq(PacketPtr pkt) override
Receive a timing request from the peer.
Definition: mem_delay.cc:146
ResponsePort(const std::string &_name, MemDelay &_parent)
Definition: mem_delay.cc:131
void recvFunctional(PacketPtr pkt) override
Receive a functional request packet from the peer.
Definition: mem_delay.cc:162
bool recvTimingSnoopResp(PacketPtr pkt) override
Receive a timing snoop response from the peer.
Definition: mem_delay.cc:172
Tick recvAtomic(PacketPtr pkt) override
Receive an atomic request packet from the peer.
Definition: mem_delay.cc:138
This abstract component provides a mechanism to delay packets.
Definition: mem_delay.hh:66
bool trySatisfyFunctional(PacketPtr pkt)
Definition: mem_delay.cc:77
RequestPort requestPort
Definition: mem_delay.hh:128
MemDelay(const MemDelayParams &params)
Definition: mem_delay.cc:46
RespPacketQueue respQueue
Definition: mem_delay.hh:132
Port & getPort(const std::string &if_name, PortID idx=InvalidPortID) override
Get a port with a given name and index.
Definition: mem_delay.cc:65
void init() override
init() is called after all C++ SimObjects have been created and all ports are connected.
Definition: mem_delay.cc:57
ResponsePort responsePort
Definition: mem_delay.hh:129
const std::string _name
Definition: named.hh:41
A Packet is used to encapsulate a transfer between two objects in the memory system (e....
Definition: packet.hh:294
bool isRead() const
Definition: packet.hh:592
uint32_t payloadDelay
The extra pipelining delay from seeing the packet until the end of payload is transmitted by the comp...
Definition: packet.hh:448
void makeResponse()
Take a request packet and modify it in place to be suitable for returning as a response to that reque...
Definition: packet.hh:1059
uint32_t headerDelay
The extra delay from seeing the packet until the header is transmitted.
Definition: packet.hh:430
bool isWrite() const
Definition: packet.hh:593
Ports are used to interface objects to each other.
Definition: port.hh:62
bool isConnected() const
Is this port currently connected to a peer?
Definition: port.hh:133
The QueuedRequestPort combines two queues, a request queue and a snoop response queue,...
Definition: qport.hh:110
bool trySatisfyFunctional(PacketPtr pkt)
Check the list of buffered packets against the supplied functional request.
Definition: qport.hh:163
A queued port is a port that has an infinite queue for outgoing packets and thus decouples the module...
Definition: qport.hh:62
bool trySatisfyFunctional(PacketPtr pkt)
Check the list of buffered packets against the supplied functional request.
Definition: qport.hh:98
const Tick writeReqDelay
Definition: mem_delay.hh:179
const Tick readRespDelay
Definition: mem_delay.hh:177
const Tick writeRespDelay
Definition: mem_delay.hh:180
const Tick readReqDelay
Definition: mem_delay.hh:176
Tick delayReq(PacketPtr pkt) override
Delay a request by some number of ticks.
Definition: mem_delay.cc:193
SimpleMemDelay(const SimpleMemDelayParams &params)
Definition: mem_delay.cc:183
Tick delayResp(PacketPtr pkt) override
Delay a response by some number of ticks.
Definition: mem_delay.cc:205
#define fatal(...)
This implements a cprintf based fatal() function.
Definition: logging.hh:190
virtual Port & getPort(const std::string &if_name, PortID idx=InvalidPortID)
Get a port with a given name and index.
Definition: sim_object.cc:126
Bitfield< 54 > p
Definition: pagetable.hh:70
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Tick curTick()
The universal simulation clock.
Definition: cur_tick.hh:46
int16_t PortID
Port index/ID type, and a symbolic name for an invalid port id.
Definition: types.hh:245
uint64_t Tick
Tick count type.
Definition: types.hh:58
const std::string & name()
Definition: trace.cc:49

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